Railway signaling system



' INVNTOR Chillo.

May 18, 1937. G. cAlLLE RAILWAY SIGNALING SYSTEM Filed March 18, 1932 131 www1.. wmlwlmu mmflwww. NNIH rw WW Q Geonges BY Q61 HIS ATTORNEY Patented May 18, 1937 UNITED STATES PATENT YOFFICE RAILWAY SEGNALING SYSTEM Georges Caille, Vaujours, France, assignor, by mesne assignments, to 'lilnie` Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application March 18,

1932,l serial No. 599,705l

In France March 20, 1931 3 Claims.

. This invention relates to railway signaling systems of the kind comprising track circuits constituted by the track rails which are subdivided into block sections provided with the usual signals for the control of traiiic through the section. 'Ihe operation of the signals is controlled by line relays and track relays in accordance with trafc conditions in advance and the invention has for its principal object to provide a system of the general character above described in which the number'of ving drawing which is a diagrammatic View of the general arrangement andcircuit connections of a section of track provided with signals controlled in accordance with one form of the invention.

`Referring now to the drawing, the track rails are indicated at d, d', and are divided by insulating joints z' into a plurality of block sections l, 2,

and 3, through which traic proceeds in the direcl tion indicated by the arrow. At the entrance end of each block section a signal Si, S2, or Si is provided, these signals being of the illuminated or light type and each comprising a green or proceed `lamp v, a yellow or caution lamp y', and a red or 'stop lamp r. In addition each or certain of the signals may comprise a pair of red lamps rX which when illuminated indicate absolute stop as shown u in the case of the signal S3.

Each block section is provided with a track vrelaysuch as VBi, VBz, or VB3, respectively, connected across the track rails and a line relay such as LB1, LB2, or LBs, respectively, controlled by the corresponding track relay.

In accordance with one feature of the invention, each block section is providedwith an approach line relaysuch as APL1 or APLz,respectively,connected in series with the corresponding line relay by line conductorssuch as Z1, l1. The circuit comprising 'Y each line relay -LB and the associated approach line relay APL is controlled by an associated ap- Y '.'50- proach track relay APV, as well as by the track relays VB of the corresponding section and of the section in advance. Each approach track relay mAPV is connected across the track rails of the section in'series'with a track battery b', and each circuit including the relays LB and APL is supplied with current from the terminals a, a" of a suitable source.

The operation of the system is as follows:

(a) Signal control by tram Let it be assumed that the blocksection 3ds occupied by a train or vehicle. The track relay VB3 is deenergized` owing to the presence of the train orvehicle and the relay contacts I0 are kconsequently opened so that the supply ofV our#l rent vto theV line relay LBz of the section 2 is interrupted. The contact il of line relay LBz there- Viore' falls to its lower position and completes a circuit from terminal a through contact I3 (closed as will be explained later by the approach of' an-"" other `train)contact lll (which is in its .upper position since track relay VBz isv energized), contact l l of relayLBz (whichis in its lower position), caution lamp y' ofsgnal S2, to the other terminal a.

The signal S2 will thus beprepared to give a caution indication to a train entering the section l as will be explained hereinafter while as regards signal S3, the track relayVBa is deenergized by` Y the presence of the train in section 3 and the contact le o f this relay being in its lower position, the circuit'of the stop lamp r of signal S3 is prepared to give a stop'indication to the followingtrain.

The system illustrated is provided'with a central control relay LC the contacts Il of which are in-- cluded in the circuit'of the relays LBzLand APLz, the energizing circuit of the relay LC including contacts l5, I6 operated by switch'leverslVlE at the control cabin, this arrangement being provided for enabling anY operator atthe cabin to`r` place the signal S3 to stop if desired lbylighting lamps rX through back contact 30.

Under the Vconditions above described, however, the circuit of the `relays LB2 and APLz is interrupted at the contacts! il of track relayVBaso" that the setting of the switch'levers l 5, I5 by the operator is immaterial. V

(b) Approach control of signal yindications The signals corresponding to4 block sections at will4 thus be deenergized and its contactlB willi' close, thus finally completing the lamp circuit of the signal S3 and causing one or another of the signal lamps of the signal S3 (as determined by the relays VB3, LBs, and LC) to be illuminated. The control of lamps v, :i and r of this signal is in accordance with usual practice and need not be explained in detail herein.

(c) Locking of central control by approaching train The relay APL1 comprises in addition to relay contact I3, relay contacts I9, I9' included in the energizing circuit of an approach locking relay EA at the signal cabin at a station for instance, the relay EA preventing the operator from throwing the switch levers I5, I5', so as to give a stop signal indication at the lastmoment to a train which is too near to the station, the relay EA being of course only eiective for this purpose if the block section adjacent to the station is unoccupied.

Let it be assumed that a train is entering block section I; relay VBi being thereby deenergized, the opening of relay contact Iii will deenergize relay APL1, the relay contacts I9, I9' of which accordingly open. Locking relay EA, is therefore, deenergized and the opening of its contact 20 causes a visible or audible indicator E1 tobe operated. The deenergization of the relay EA also causes a relay contact 22 to open which deenergizes an electric locking device 23. The latter when deenergized locks the switch levers I5, I5', and prevents the operator from causing a stop signal to be given by the signal S3.

If however when the train enters section I, another train is already occupying block section 3, the action above described does not take place since track relay VB3 is deenergized by the presence of a train in block section 3 and contacts 24, 24' of the relay VB3 are in their lower position in which a supply of energizing current to the relay EA is provided through a circuit not including the open contacts I9, I9.

(d) Control of track contact Each block section is shown as provided with a track contact device C1, or Cz, for repeating the signal indication on the locomotive.

Let it be assumed that block section 3 is occupied but that block section 2 is unoccupied; relays VBa and LBz are deenergized and Contact 25 of relay LBz is thus closed. A circuit is thus completed from terminal a to contact device C1,

thence through a suitable indicating device on the locomotive (not shown), track rail d', contact 25 and Contact SI of relay VBz (closed since relay VBz is energized) to the other terminal a. An indication is thus given on the locomotive that block section 2 is unoccupied.

If, however, block section 2 is occupied, relay VBz is deenergized and relay contact 3| would be open so that current is not supplied to the track contact C1 and a corresponding indication is given on the locomotive.

Let it be now assumed that a contact is eiiected accidentally between the line wires Z1, Z1', for example at the point .r in block section I, and

` that a train enters this block section. If the approach track relay APV1 were not provided the opening of contact I of the relay VBr owing to the deenergization of this relay by the train tions of the relays coupled together in the same block section, the approach track relays APVi, APVz are provided in accordance with the invention, each of these relays being arranged as shown to control the corresponding approach line relay in the same manner as this latter relay is controlled by the corresponding track relay VB.

As above stated and as illustrated in the drawing the approach track relay APV is connected across the track rails d, d', of the block section in series with the battery b, which also serves as a track battery for the corresponding track relay VB. The resistance of the energizing winding of the relay APV is so proportioned relative to the voltage of the battery b, that when as is the case under normal conditions, the two relays APV and VB are in series with one another, the sum of the resistances of their energizing windings is too large for the current circulating in the windings of the relays to be suflicient to operate the relay APV, this current being however su'- cient to energize the track relay VB. When however a train enters the block section 2, the relay VB is short-circuited and the consequent decrease in the resistance of the circuit causes the current traversing relay APV to increase to such a value that this relay is operated. It will thus be seen that therelays APV are normally deenergized, whilst the track relays VB are normally energized, each of the vrelays APV, being only energized when a trainenters the corresponding block section `and short-circuits the corresponding relay VB. If therefore a train enters block section I, whilst a contact is established at :I: between the line wires Z, l', the energization of relay APV1 opens the relay contacts 26 so that the energizing circuit of relay APL1 is interrupted in spite of the accidental contact at From the above description it will be apparent that the invention as illustrated enables the following control conditions to be obtained with only two line wires.

1. A stop signal indication to be given by the illuminated or other signal protecting a block section which is occupied.

2. A caution signal indication to be given at the signal to the rear of the signal displaying a stop indication.

3. A proceed signal indication to be given at the signal to the rear of the signal displaying the caution indication.

4. The track contact device is rendered effective when a signal is displaying a caution indication.

5. The light signal is arranged to be illuminated by the entrance of the train into the block section preceding the signal.

6. Thek locking of the signal control by the operator when a train is approaching.

All or certain of these conditions may be embodied in a signaling system incorporating the invention and the system may also comprise additional controlling arrangements or devices as may be required to effect the control of trafli in any particular case. l

a track circuit for said section including the usual source of current and the usual normally energized track relay, an approach track relay interposed between said source and one of the rails and normally deenergized but arranged to become energized when a train occupies the section, an approach lighting relay, a circuit for said approach lighting relay including a front contact of said usual track relay and a back contact of said approach track relay, and a signal 5 in advance of said section having a lighting circuit including a back contact of said approach lighting relay.

2. In combination, a stretch of railway track divided into sections, a track circuit for each 20 section including the usual source of current and the usual normally energized track relay, an approach track relay for each section interposed between said source and one of the rails and normally deenergized but arranged to become 25 energized when a train occupies the section, a line relay and an approach lighting relay for each section, a line circuit for each section including the associated line relay and approach lighting relay and controlled by a front contact of the associated usual track relay and a back contact of the associated approach track relay/ as well as by a front contact of the usual track relay for the section next in advance, and a signal for each section controlled by the associated track relay and line relay as well as by the approach lighting relay for the section next in the rear.

3. In a railway signaling system, the combination of a section of railway track; a signal for said section, capable of displaying an absolute stop indication; means for automatically controlling said signal in accordance with trac conditions in said section, manually controlled means for causing said signal to display said absolute stop indication, and means operated by the approach of a train within a' predetermined distance from said signal for rendering said manually controlled means inoperative to cause said signal to display said absolute stop indication.

GEORGES CAILLE. 

